Lycium barbarum polysaccharide prevents focal cerebral ischemic injury by inhibiting neuronal apoptosis in mice

PLoS One. 2014 Mar 3;9(3):e90780. doi: 10.1371/journal.pone.0090780. eCollection 2014.

Abstract

Aims of the study: To investigate the neuroprotective effect of Lycium barbarum polysaccharide (LBP) on focal cerebral ischemic injury in mice and to explore its possible mechanism.

Materials and methods: Male ICR mice were used to make the model of middle cerebral artery occlusion (MCAO) after intragastric administration with LBP (10, 20 and 40 mg/kg) and Nimodipine (0.4 mg/kg) for seven successive days. After 24 h of reperfusion, neurological scores were estimated and infarct volumes were measured by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. Morphological changes in ischemic brains were performed for hematoxylin-eosin (HE) staining. The number of apoptotic neurons was detected by TUNEL staining. The Bax, Bcl-2 protein expression and CytC, Caspase-3, -9 and cleaved PARP-1 activation were investigated by immunofluorescence and western-blot analysis.

Results: LBP (10, 20 and 40 mg/kg) treatment groups significantly reduced infract volume and neurological deficit scores. LBP also relieved neuronal morphological damage and attenuated the neuronal apoptosis. LBP at the dose of 40 mg/kg significantly suppressed overexpression of Bax, CytC, Caspase-3, -9 and cleaved PARP-1, and inhibited the reduction of Bcl-2 expression.

Conclusions: Based on these findings we propose that LBP protects against focal cerebral ischemic injury by attenuating the mitochondrial apoptosis pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Apoptosis / drug effects*
  • Blotting, Western
  • Brain Ischemia / prevention & control*
  • Dose-Response Relationship, Drug
  • Drugs, Chinese Herbal / administration & dosage
  • Drugs, Chinese Herbal / pharmacology*
  • Fluorescent Antibody Technique
  • In Situ Nick-End Labeling
  • Infarction, Middle Cerebral Artery
  • Male
  • Mice
  • Mice, Inbred ICR
  • Neurons / drug effects*
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases / metabolism

Substances

  • Drugs, Chinese Herbal
  • lycium barbarum polysaccharide
  • Parp1 protein, mouse
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases

Grants and funding

The authors gratefully acknowledge the financial support provided by the National Natural Science Foundation of China (Grant no. 81360649), Natural Science Foundation of Ningxia (Grant No. NZ13278), Research Project of Education Department in Ningxia (Grant No. NGY2012059), and the Research Project of Ningxia Medical University (Grant No. XM2011017). The authors are indebted to the staff in the animal center and the Science & Technology Centre, who provided assistance in the study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.